topic Re: Informix causing high CPU system time in Operating System - HP-UX

Informix causing high CPU system time

Colin Rice — Tue, 25 Sep 2001 05:15:56 GMT

Hi

We are running 6 DB instances of Informix 7.24UC7 on N4000 w/HP-UX 11.0. Whenever the system is running for > 2 weeks, the system time accumulates day-by-day until it hits 35-40%, after which our users cannot work.

Anyone had this kind of problem??

Statistics on Systems Performance of eagle on Mon Sep 24 17:00:03 EAT 2001
--------------------------------------------------------------------------

System Load Average
--------------------
5:00pm up 22 days, 10:27, 188 users, load average: 6.41, 6.57, 7.09

Output of sar in 10 counts with 5 seconds interval
%usr %sys %wio %idle
--------------------------------------------------

HP-UX eagle B.11.00 U 9000/800 09/24/01

17:00:08 %usr %sys %wio %idle
17:00:13 11 39 26 24
17:00:18 8 36 41 15
17:00:23 10 35 40 16
17:00:28 13 39 29 19
17:00:33 19 40 36 6
17:00:38 13 39 32 16
17:00:43 14 39 30 17
17:00:48 13 36 38 13
17:00:53 14 39 25 22
17:00:58 11 38 22 29

Average 13 38 32 18

Re: Informix causing high CPU system time

Animesh Chakraborty — Tue, 25 Sep 2001 06:51:19 GMT

Hi,
It seems that your system is heavily loaded.
How much memory you have and how many CPU ?

Regards
Animesh

Re: Informix causing high CPU system time

David Navarro — Tue, 25 Sep 2001 07:07:33 GMT

Hi, I can see you are spending a lot of time in system tasks and io waits, maybe you have a problem with memory, that is you're swapping a lot and your system is busy with that swap, in system calls and disk io.
Maybe any patch ??, send us you memory configuratios, and a vmstat -s output and swapinfo -t.

Re: Informix causing high CPU system time

Praveen Bezawada — Tue, 25 Sep 2001 07:18:29 GMT

Hi
Monitor the system through Glance or you can use the below set of commands

sar -o sarfile 5 5
sar -Af sarfile > sarfile.report

The output in report file gives a clearer picture of what's actually happening. For a start you look for below symptoms

If swpot/s (swapouts per second) is frequently greater than one, the system is memory bound. If swpocc (percent swap queue is occupied) is greater than five, the system is memory bound. In either case, add more memory to the system.

If %rcache is frequently less than 90 or %wcache is frequently less than 65, the buffer cache is too small. Increase the value of the kernel's bufpages parameter and generate a new kernel.

If %idle is frequently equal to zero, or if runq-sz (runqueue size) is frequently high (eight or more), the system is CPU bound. If system throughput is less than desired, upgrade to a faster processor or reduce computational load on the system.

Check the capacity of the system tables for processes, inode cache, and file descriptors. These are labeled proc-sz, inod-sz, and file-sz. If the current utilization is too close to the maximum available, increase the corresponding HP-UX kernel parameter (nproc, ninode, or nfile). When increasing nfile, increase nflocks proportionally.

Hope this helps...
...BPK...

Re: Informix causing high CPU system time

jok llamera — Wed, 26 Sep 2001 07:06:40 GMT

hi

We are using 8Way server and 6Gb of memory. Also attached sar output.

tnx,
walter